Published online Jan 7, 2019. doi: 10.3748/wjg.v25.i1.95
Peer-review started: September 12, 2018
First decision: October 24, 2018
Revised: December 1, 2018
Accepted: December 13, 2018
Article in press: December 13, 2018
Published online: January 7, 2019
Processing time: 118 Days and 1.2 Hours
Abdominal pain-predominant functional gastrointestinal disorders (AP-FGIDs) are a common clinical problem in paediatric practice across the globe, with an estimated prevalence of 13.5%. Although thought to be benign in nature, as a group they are known to associate with poor health-related quality of life and high healthcare burden.
The pathophysiology of AP-FGIDs is not clearly understood. Previous studies have shown abnormalities in gastroduodenal motility, such as delayed gastric emptying, impaired antral motility, and impaired gastric accommodation as potential pathophysiological mechanisms in children. Studies among adults have found autonomic dysfunction in patients with IBS. However, the association between autonomic dysfunction and gastric motility in children with AP-FGIDs had not been previously evaluated.
The main objective of our study was to assess the autonomic functions in children with AP-FGIDs and their relationship to gastric motor functions.
One hundred children fulfilling Rome III criteria for AP-FGIDs and 50 healthy controls aged 5 to 12 years were recruited for the study. All patients were thoroughly investigated to rule out underlying organic disorders. Gastric motility and cardiovascular autonomic functions were assessed using validated, non-invasive techniques.
Gastric emptying rate, amplitude of antral contractions, and antral motility index were significantly lower in children with AP-FGIDs. Autonomic functions, including blood pressure and heart rate responses to standing from lying down position, heart rate response to deep breathing, and Valsalva test, showed no difference between children with AP-FGIDs and controls. These parameters did not show any correlation with gastric motor functions. However, the duration of pain episodes negatively correlated with the parasympathetic tone.
Although children with AP-FGIDs have abnormal gastric motility parameters, their cardiovascular autonomic functions are normal. In addition, there is no correlation between autonomic functions and gastric motility. Our findings indicate that the autonomic nervous system is not chronically abnormal in patients with AP-FGIDs. Based on currently available evidence, we propose maladaptive parasympathetic flow and an automated stomach model as a potential pathophysiological mechanism for AP-FGIDs.